Refrigeration systems have existed for years. Although a wide variety of refrigeration systems exist, the majority of refrigeration systems in use today use a chlorofluorocarbon (CFC) refrigerant such as FREON brand refrigerant manufactured by DuPont Chemicals, unit of E.I. DuPont de Neumours. In automotive air conditioner applications, the most popular refrigerant in use today is a CFC refrigerant known as "R-12." In residential and commercial buildings, the most common refrigerant is a refrigerant known as "R-22."
Problems exist with these refrigerants in that both are believed to have an adverse environmental impact. In particular, R-12 refrigerant is believed to contribute substantially to the depletion of the ozone layer in the atmosphere. To reduce the environmental damage caused by these CFC refrigerants, and in particular R-12, the Government of the United States, and governments of other countries have instituted regulations which will require refrigeration systems manufacturers and owners to reduce, and ultimately cease using R-12 refrigerant within the near future. Already, manufacturers of R-12 refrigerant have substantially reduced the quantities of R-12 refrigerant manufactured, thus substantially decreasing the availability of R-12 refrigerant.
Although R-12 refrigerant will no longer be available, refrigeration systems using R-12 refrigerant will still exist and be in use. As such, these R-12 refrigeration systems will, from time to time, require replenishment of the refrigerant. Because of the likely unavailability of R-12 refrigerant in the near future, an alternate refrigerant will be needed to replace the R-12 refrigerant that is more "environmentally friendly" than R-12. One such environmentally friendly refrigerant is a refrigerant designated as "R-134A." Although refrigerant R-134A has been found to be an effective refrigerant, problems exist with its use in R-12 refrigeration systems. Primarily, these problems relate to R-134A's incompatibility with R-12 refrigerant, and the incompatibility of the lubricating oils used with R-12 and R-134A. Because of this incompatibility, the R-12 refrigerant and mineral oil must be removed from a refrigeration system before R-134A refrigerant (with lubricating oil) is placed into the refrigeration system. Once R-134A refrigerant is placed into the system, it is important to not put any R-12 refrigerant back into the refrigeration system which then contains R-134A. The cross contamination of R-12 and R-134A refrigerant could cause considerable damage to the refrigeration system and any service equipment used on the refrigeration system.
To help ensure that R-12 refrigerant is not placed into a refrigeration system containing R-134A refrigerant, standards have been created that mandate that the type of refrigerant port used for refrigeration systems containing R-134A refrigerant be different than refrigerant ports in refrigeration systems using R-12. In refrigeration systems that previously contained R-12, a new refrigerant port, or conversion firing as required by SAE Standard J1661 must be fired over the existing refrigerant port. This new refrigerant port must contain the "R-134A profile," (SAE J639) in order to enable R-134A refrigerant to be introduced into the refrigerant system.
Although the profile of the R-134A refrigerant port has been established by the Society of Automotive Engineers, the production of a retro-fit R-134A port has not been that simple and straight forward. In particular, it has been difficult to create a refrigerant port which contains the R-134A profile, and which does not require an undue amount of additional space. Another desired feature is to create an R-134A conversion or retro-fit port that will be difficult to remove once installed. The R-134A retro-fit refrigerant port should be difficult to remove to reduce the likelihood that a user will later remove the 134A refrigerant port so that he can reintroduce R-12 refrigerant back into the refrigeration system.
Therefore, one object of the present invention is to provide a retro-fit R-134A port which both minimizes the additional space required for the port, and is difficult for a user to remove.
Another aspect of the conversion of a refrigeration system from one using R-12 refrigerant to one using R-134A refrigerant is to provide a suitable coupling member for enabling a refrigerant service line to be coupled to the refrigerant port. As will be appreciated by those familiar with automotive engineering, the engine compartments of automobiles are becoming more and more crowded. Various regulations relating to air quality standards and gas mileage standards, along with an increasing array of optional equipment, have caused a severe shortage of space or "real estate" under the hood of a car. This shortage of "real estate" in the engine compartment has increased the difficulty of performing service on automobiles, because of the difficulty in getting a tool (such as a wrench or refrigerant servicing coupling) to the part that needs to be serviced. This problem is particularly acute with newer model cars, and with the refrigerant servicing ports on the refrigeration (air conditioning) systems of these newer cars. Compounding this problem is the larger size of most field service couplings used to service R-134A systems.
Prior refrigerant couplings typically were generally cylindrical in nature. At one end of the cylinder was the orifice which fit over the refrigerant port to engage the coupling member to the refrigerant port. A refrigerant servicing line extended axially outwardly at the opposite end of the cylindrical coupling or perpendicular to the axis out the side of the body. As will be appreciated, a coupling with the hose extended axially would generally have an effective length which extended from the receiving portion of the coupling to that portion of the hose which could be "bent away" from a straight line relationship with the coupling. Thus, it will be appreciated that such a coupling would tend to have a relatively long overall effective length. Unfortunately, couplings such as the ones described above (even those with the hose extended perpendicular out the side of the body) often can be too long for use with some automotive vehicles (and some other building-based systems) wherein length restrictions preclude the use of such a relatively long coupling. This problem of too lengthy couplings is made even worse when the conversion fittings are used, which extends the length of the male fitting also. Examples of prior art refrigerant coupling members are those manufactured by the Aeroquip Corp., Classic Tool, Master Cool, T.I.F., and the Assignee, K-Whit Tools, Inc.
It is therefore also one object of the present invention to produce a refrigerant coupling member which overcomes this problem by having a relatively more compact size and a reduced effective length, to foster the use of the coupling in places where longer-length couplings will not work.